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Re: bird flight



It may be a few years late.  Refer to Dial's paper on changes in pigeon
and magpie beat kinematics and joint loci with changing airspeed as one
of many papers on the subject for various avian species.   And my first
talk about variations in the kinematics of pterosaur wingbeats was at
SSA '99 and I have given other talks on the subject several times
since.  My talk at the Toulouse pterosaur conference in 2001, was
entitled "A Skeletal Mechanism With Application to Automatic Gust Load
Alleviation in the Azhdarchidae", and in addition to other things, it
addressed specializations for torsional flexion in the phalanges of the
wingfinger and the equations required to quantify them.  We are
presently starting to consider arthritic ornithocheirid joints in an
effort to address usual ranges of motion of several joints in pterosaur
wings.  Jeremy Rayner has done a good bit on pterosaur wingbeat
kinematics as well.  However, there is always room for more  work on the
subject and more workers.
Jim

Mark Hallett wrote:

> Ken, I was wondering when someone would point this
> out--I think it has tremendous implications for
> pterosaur flight as well as for birds. In the case of
> at some pterosaurs (Pteranodon ingens, for example)I
> suspect there is an added factor in that the outer 4th
> finger phalanges appear to have been capable of
> considerable torsional rotation, based on a "study" of
> these I once did on paper. You're right--rich acedemic
> pastures for graduate students! --Mark Hallett
> --- Ken Carpenter <Kcarpenter@dmns.org> wrote:
> > In watching the documentary "Winged Migration"
> > (briefly discussed previously on the DML), I note
> > that the wing tips of various birds do not move in
> > the exact same pattern (I use wing tip simply
> > because it is an easy reference point to trace bird
> > wing movement). Although closely related birds have
> > similar wing tip movement patterns, more distantly
> > related birds don't. This got me wondering if the
> > "one-size-fits-all" model of bird flight is correct.
> > The tremendeous variation in wing shape (long,
> > tapering of gliders, versus short, broad of
> > flappers) would suggest that there may be more
> > subtle variation in wing movement than realized.
> > Certainly the variation in humeral heads among birds
> > suggests that this may be so. The standard model of
> > bird wing motion is the figure "8". In some footage
> > in the flm of a duck flapping its wings a little,
> > the wing tip clearly did not move through the figure
> > 8, rather it seemed to move in a "O" at the most.
> > Perhaps bird flight needs a new assessment!
> >  (graduate students: hint, hint).
> > Kenneth Carpenter